Compound internal-combustion engine.



R. M. PIERSON.

COMPOUND INTERNAL OOMBUSTION ENGINE. APPLIoA'noN FILED Amm-1, 1906.

967,828. Patented Aug. 16, 1910.

Hoi' Gas Explosion Comprsssiou A' Exhaus AImissio". /5-1 f7 Mr* fvg .Rdmission- UNITED STATES PATENT OFFICE.

ROBERT M. PIERSON, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO C. P. POWER COMPANY, 0F NEWARK, NEW JERSEY, A CORPORATION 0E NEW JERSEY.

COMPOUND INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Aug. 16, 1910.

To all whom it may concern;

Be it known that I, Romani M. PIERsoN, a citizen of the United States, residing at New York city, in the county and State of New York, have invented certain new and useful Improvements in Compound Internal-Combustion Engines, of which the followingV is a specification.

This invention relates to internal-combustion engines in which both the compression and expansion processes are compounded or conducted in stages, and its Object is t0 minimize the number of cylinders and moving parts required to perform the engine cycle, and to secure improved mechanical balance and other advantages. This object is attained by employing the same cylinder for the low-pressure stage of both the compression and expansion processes, and alternat-ing the compressor and expander functions ofthe low-pressure cylinder to accommodate the phases of the high-pressure cylinder, which ma be of the four-cycle type. Mechanical alance is attained by causing the high-pressure and low-pressure pistons to move in opposite directions, as for instance by mounting the cylinders alongside each other and connecting the pistons with cranks set 180 apart.

Of the accompanying drawings, Figure 1 represents a sectional View of a compound explosive engine constructed according to my invention. Fig. 2 is a view showing the cam and valve-rod for Working the pistonvalve on the low-pressure cylinder. Figs. 3 to 6 inclusive are diagrams of the cylinders and pistons illustrating the four phases making up the cycle of the engine.

The same reference characters indicate the same p. rts in all the views.

In the drawings, 10` is a crank-shaft having two cranks' 11, 12 at 180 and a flywheel 13.

14 vis the high-pressure cylinder with trunk-piston 15 connected by pitman 16 with the crank 11; and 17 is the low-pressure cylinder having piston 18 and pitman 19 on thecrank 12.

The two cylinders are connected by two conduits, one being a pipe 20 for conduct-- ing the com ressed charge from L. P. cylinder 17 to P. cylinder 14, and the other being a pipe 21 for conductin the exhaust of the H. P. cylinder into the P. cylinder.

Cylinder 14 has the usual appurtenances l of a four-cycle explosive engine, namely the inlet-valve 22, here shown as an automatic or suction-operated check-valve an exhaustvalve 23 operated from a half-speed cam 24, and an igniter 25 timed to give a spark in the usual manner.

Cylinder 17 is equip ed to alternately perform the functions o a compressor and an expander. I have here shown this cylinder adapted to compress a charge of pure air only, although the charge admitted might be fuel-laden.

26 is a suction-operated air-admission check-valve and 27 is an automatic pressureoperated discharge check-valve. Forl seating the latter with an extra pressure when 'the high-pressure exhaust, which may be above the compressor-'dischar e pressure,

enters cylinder 17 I show a ha f-speed camV 28, rod 29, and tappety 30 actin onva heavy valve-seating sprlng 31, whic acts only during the hot-gas-admission phase, occurring as hereinafter described.

32 represents a piston-valve which connects a port 33 in L. P. cylinder 17 alternately with the hot-gas admission-pipe 21 of said cylinder and with the exhaust-pipe 34 thereof. This valve is operated by a halfspeed cam 35 acting 4on the valve-rod 36. Fig. 2 shows the four quadrants of said cam.

37 represents a suitable intercooler 1ocated in the compressor-discharge pipe 2O and adapted to remove the heat of compression froni'the charge. In this pipe beyond the intercooler 37 is placed a float-feed carbureter 38, of ordinary type except that intercooler-pressure is led to the surface of the fuel in the iioat-chamber through a duct 39 and the liquid fuel requires to be supplied to the float-chamber under a pressure superior to intercooler pressure.

In the hot-gas or receiver-conduit 21 is placed a jet-mixer 40 similar in construction to the carbureter 38, but receiving water instead of fuel, and spraying said water into the products of combustion passing through pipe 21, thereby conserving their heat in a lower-tem erature and more stable form, which ena les the resulting mixture of steam and products of combustion to be em loyed expansively in the low-pressure cylin er 17, much as steam would be in an ordinary steam-engine. Thiswater-quencher for the gases is one of several typesfwhich may be used and I do not confine myself to any one .l type. f The operation of my invention is illus- 5 trated in a simple'fashion by the fourdiaammatic phases shown in Figs. 3 lto 6, om. which it will be seen that the H. P. motor acts-like an ordinary four-cycle engine, vonly at'higheradmission, exhaust, and 'explosion pressures, While the L. P. motor acts alternately as compressor to supply the first-stage compression for the charge enter- -ing the'H. P. cylinder and as expander to 'perform a second stage of expansion for the exploded. gases while. doing useful Work. Taking these phases in order as represented by Figs. 3 to 6 they are v.(1) Explosion 1n H. P. coincides with low-pressure compression in L. P., and valve 27 is the only valve opened, the air-char e beingstored m'the intercooler 37 durin t e latter part of this phase and the who e of .fthe next'one. d (2) Exhaust from H. P. coincides with 2'5' hot-gas admission to L.'P. and low-pressure expansion of the gases in the latter. Valve 5.23 is open and valve 32 is above port 33. Tappet puts extra spring-pressure on valve27. 30" Charge-admission to H. P. coincides with exhaust of expanded gases from L. P. `A`Valve 22 is open and valvel 32 is belovT port 33.` (4) High-pressure compressioninpH.; P.' 35 coincides with atmospheric air-admission to .Y L. P., and valve 126 is the only one opened. Thereupon the cycle is repeated. It willv .be noted that there is positive torque on thecrank-shaft through phases (1)-, (2)', ,4'0 and (32 and negative torque only durin phase 4), which givesV this engine an a vantage overl ordlnary single-cylinder or double-cylinder four-cycle engines in the matter. of `torque and enables a comparatively light` fly-wheel to bel used, while the lmechanical balance is Aas goodjas that of three-cylinder, four-cylinder and doublecylinder opposed four-cycle en es. In the'matterof simplicity and relia ility this 5,() enl'gline is somewhat better than prior twohcy lnder simple'explosion engines since only one igniter 1s required, and the eiciency is far higher than that of simple explosion enginessince the maximum pressure-range is very considerably extended by compounding both the .compression and expansion processes; To properly stand the high explosion pressures, the high-pressure parts are heavily constructed and the cylinder .60 .and piston are of. relatively-small diameter,

. as shown.

I do not broadly claim an internal-combustion cycle :compounded on both the comvpression and expansion sides, but believe myself to be the first to provide a combination of hi h-pressure and low-pressure cyllnders per orming a true compound cycle in which the low-pressure cylinder is both compressor and expander for the high-pressure cylinder.

If continuous positive torque is desired it may of course be attained b a suitable dusllcation of the two-cylin er unit herein escribed, or of one or more of its cylinders,

with a proper relative disposition of the phases of the respective units.

Water pumped under a pressure superior to the P. exhaust pressure and (as here shown) first heated by passing through the H. P. water-jacket, is maintained at a fixed level in the float-chamber 43 of the jetmixer 40, to Which the H. P. gaseous exhaust pressure is admittedthrough a duct 41. Water-spray is then drawn into the hot-gas current from the spray-nozzle 42vof the mixer on the atomizer priciple, as in ordinary `jet carbureters.

`In cases where the conditions admit of locating the high-pressure and law-pressure cylinders very close together, water-coolin of the hot gases may be omitted if desire as they wil lose very little heat in traversing a short port. In thatl case it may be vdesirable to substitute a suitable lift-valve mechanism for the slidin piston-valve 32 shown in the drawings. t will be understood that the valve-arrangements for effects in gifthe 'desired sequence of operations may bef-varied in many particulars without departing from my lnvention.

Regulation of the engine for speed` and lload may b e performed by throttling the air-suction of thelow-'pressure cylinder, o r holding open its admlssion-valve forl art of the compression-stroke, or in any o the well-known-Ways for regulating compressors, or the regulation may be applied to the high-pressure A motor, by thrott ed chargeadmission, variably-timed' ignition, etc.

1. In a compound internal-combustion -motorapparatus, the combination of a highpressure member adapted to isolate a compressed charge and to burn and partially expand the same, and a low-pressure memb er adapted .during alternate phases to compress-the charge for said high-pressure member and to expand the gases received there-- from, together with valve-mechanism between said members for alternately admittin the charge from the low-pressure to the lhig -pressure member'and admitting -the gases from the high-pressure to the lowpressure member.

2. In a compound internal-combustion motor ap aratus, thecombination of a fourcycle hig -pressure member adapted to isolate a partially-compressedcharge, further compress and explode the same and partially expand the gases, and a low-pressure member connected with said high-pressure member by separate eiiiux an influx conduits,

together with valve-mechanism ,associated with the high-pressure member for producing its phases, and valve-mechanism associated. with the low-pressure member for producing therein alternate compressing and expanding phases.

3. In combination, a high-pressure explosive compressor-motor member, a lowpressure member compounded therewith and having means which constitute it alternately a charge-compressor and an expander of the products of combustion, a conduit for conductin the charge from the low-pressure to the ii h-pressure member, and means for cooling the charge between said members to avoid pre-ignition. p

. An engine comprising high-pressure and low-pressure cylinders with pistons therein connected to work oppositely, valvemechanism and i ition-mechanism for the high-pressure cylinder arranged to produce a four-stroke explosive cycle therein, a compressed-charge conduit and a hot-gas conduit connecting the two cylinders, and valvemechanism for the low-pressure cylinder adapted to alternately produce therein a low-stage compression of the working charge, and a' ovv-stage expansion of the exploded gases.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses, the 13th day of August 1906.

ROBERT M. PIERSON. Witnesses: 1

Gr. W. HOPKINS, Gr. BLAKE. 

